This list is based on my own research, augmenting the very helpful but sometimes unreliable, CrunchBase database. The funding includes VC contributions as well as investments by established companies.

In the two years that I've been compiling and tracking this list, it has changed considerably. Cloudera was the most-funded big data startup on the March 2013 list and is still the most-funded big data startup today. But Cloudera, Mu Sigma, MongoDB, and DataStax are the only companies on today's list that were on it two years ago. And, reflecting the recent increase in the size and scope of venture capital investments, one of the companies that is new to the list, Dataminr, has raised $130 million in just one round of funding last month, a sum that would have put it as number 2 on the 2013 list.

Another company new on the list, Insidesales.com, has raised "only" $60 million last month, $40 million less than in its previous round. It may well be yet another case of company founders and exiting investors agreeing to accept funds from investors eager to invest (or up their previous investment) in a promising company. One of the original investors in Insidesales.com was Josh James who co-founded Omniture, a web analtyics company that was sold in 2009 to Adobe for $1.8 billion. James went on to found Domo in 2010 and raised an impressive $125 million in February 2014 because investors were eager to bet on whatever he was betting on.

Earlier this month, Domo announced that it has raised a new $200 million funding round at a $2 billion valuation. James told Re/Code that "the company will be ready to go public in six months." When it does so, it will join Hortonworks, a startup that used to be on this list and went public in December 2014 after raising $248 million.